Antiskid device for motor vehicles



Dec.5,1950 E. HOFFMAN ETAL 2,532,309

ANTISKIQYPEVICE FOR MOTOR VEHICLES U, Filed April 14, 1948 i 5 Sheets-Sheet l WQ N \ n I 32 INVENTORS EDWARD J. HOFFMAN \NlLLlAM 5. HARDY BY ADAM a. FRIES ATTORNEY Dec. 5, 1950 E. J. HQFFMAN ET AL 2,532,309

ANTISKID DEVICE FOR MOTOR VEHICLES Filed April 14, 1948 5 Sheets-Sheet 2 INVENTORS EDWARD 0'. HOFFMAN WILLIAM G HARDY BY, ADAM J. FRIES ATT RNEY Dec. 5, 1950 E. J. HOFFMAN ET AL ANTISKID DEVICE FOR MOTOR VEHICLES 5 Sheets-Sheet 3 Filed April 14, 1948 HARDY INVENTORS JG. HOFFMAN EDWARD WILLIAM y ADAM J FRIES ATTORN EY Dec. 5, 1950 E. J. HOFFMAN ET AL 2,532,309

ANTISKID DEVICE FOR MOTOR VEHICLES Filed April 14, 1948 5 Sheets-Sh en 4 49 [7 5%. .D V4:3 4G

INVENTORS, 21 EBWARD HOFFMAN W ATTORNEY Dec. 5, 1950 E. J. HOFFMAN ET AL 2,532,309

ANTISKID DEVICE FOR MOTOR VEHICLES Filed April 14, 1948 5 Sheets-Sheet 5 llllilllllllilllill|llllll ll1i JNVENTOR. EDWARD a. HOFFMAN WILLIAM cs. HARDY BY ADAM a. FRIES ATTORNEY Patented Dec. 5, 1950 UNITED STATES PATENT OFFICE 2,532,309 ANTisKii) mime: FOR Moron VEHICLES same i. Hartman; William G; has, and Ada-m J1 Fries, Pittsburgh, Pa'. replicates Ate! 14, rats, Serial No; 21,078 14 oisiui's. (oi. 152--214) I V hr invention relates to anti-skid devices that are particularly suitable for use on the wheels or motor cics and which'can' readily be applied to various existing models of veh 1' w "b corporated as a part the vehicle at the factory.

One object of our inventionlis to provide an' anti-skid device or the character referred to which can readily be anplied to an femovedir'om standard types of vehicles simply through removal of the wheels therefrom.

Another object of our invention. is to provide an anti-skid device that can. readily be thrown into and out of operation by the vehicle driver and wherein provision is made for idling movement of the anti-skid members upon encountering an obstruction when the anti-skid elements are in inoperative position with reseedtto the vehicle wheel. v

Still another object of our invention' is to provide an anti-skid structure wherein the cleats that are engaged by the tire and the roadwav will yield readily in various directions and'will still be fully efiective to perform their function as antiskid and traction elements.

In the accompanying drawings, Figure l. is a View partly in section and partly in elevation showing the anti-skid device mounted over a brake drum and in operative position on a tire; Fig. 2 is an outer face view of the anti-skid structure; Fig. 3 is a plan view on an enlarged scale showing the parts of the operating mechanism in the positions occupied thereby when the anti-skid cleats are on a tire as in Fig. 1; Fig. 4 shows certain of the parts at an intermediate stage of their movement toward disengagement of the anti-skid elements from the tire; Fig. 5 shows the members of Fig. 3 in the positions occupied thereby when the anti-skid elements ar moved to inoperative position from the tire; Fig. 6 is an enlarged sectional View of a portion of thestructure of Fig. 1; Fig. '7 is a View similar to Fig. 6 but showing one of the anti-skid cleats swung to its inoperative position with respect to the tire; Fig. 8 is an enlarged view of the cleat assemblyand certain of its operating elements taken on the line VIII- VIII of Fig. 6; 9 is a perspective view on an enlarged scale of one of the latch elements of Figs. 3 to 5; Fig. 10 is'an enlarged view taken'on the line X--X of Fig. 3; Fig. 11 is a view of a portion of the structure of Fig. 1, with a. latch bolt at an intermediate point between its fully released and its latching position; Figs. 12 and 13 areen larged views taken on the lines XIIXII and XIII-XIII of Figs. 4 and 5 respectively; Fig. 14 shows a modification of the'manual operating 2 mechanism of Fig. 2'; 15 shows still another" modification thereof, and Fig. 16 shows means for electrically moving the antiskid elements to their operative and inoperative positions. g

y It will be understood that each rear. wheel of a. motor vehicle will be equipped with the apparatus shown in Figs. 1 to 13' and will be operated by the vehicle driver in a suitable manner, to move the anti-skid cleats into' and out" of open.- ative position'on the tire as hereinafter explained.

The apparatus may readil'y be applied to' varione standard fo msoi motor vehicles, and as here shown, has a ba e member ii? of cylindricalfo'r rn which can sli'd over the brake drurn' 52, from the outer end ofth'e'axle, when thewheel' 8 is removed from the vehicle. The base rnember IE3 is connected to a' plate Qthat is fixedly mounted on axle housing '5 at the inner side of the drum, by a ring 515 which may be split on a line across its" periphery, to permit'it to conveniently be sprung into time iind the axle and against the inner face'o'f the ated, the ring being attached to'such inner faeeby suit-aisle screws;

The anti skid elements and the operating mechanism therefor are mounted in unitar rel'ation with the basering It. A stationary cam' ring it issecured t'olthe base ring it by" screws. i'i also rigidly connect the base ring to the ring H. A moi/able camnngit loosely encircles the base it and has cainming surfaces i' la that co-oijeratewith camlning' surfaces tladon the ring 3 to efiect relative expansive movements of the two'rings\vheii;th'e'i'ing 5 1 isg'iven'rotative move mentin one direction; as shown more clearly in FigsJ3'to 5;

A cleat ring zsis rotatably'inourited out-he base member H3, between guide rings 2! and 22 that aire rigidly secured to the member iii. A pluj-i rality of clea t assernblies il ai are pivotally con} nected to cars 26 that are bolted to the ring 29. Each of these'cleat assembliescomprisesa lever 23 of bell-crankcfcrm thatig pivotally mounted on arpivot stud iiilthat extends through the ears 25.

\ The outer arm of the bell crank lever carf'riesa' wing nut and its bolt in holding the cleat firmly on the arm 3 i.

A spring 36 has intermediate portions wrapped around the studs 29 and 39. The spring has an extension 3? that abuts against the ring 29 and is so tensioned as to rock the lever 29 in a counterclockwise direction when the lever end 29a is released. by the cam ring it for partial swinging movement. The upper portion 3'ia of the spring 36 biases the cleat-carrying arm 3| in a clockwise direction.

By reason of this arrangement of the spring 36, the cleats and their arms will yield toward and past the position indicated by the dotted lines in Fig. 6, upon some compression of the tire when traveling or if the tire becomes flat, without injury to the cleat assembly. The cleats 32 may suitably be made of spring steel.

When the cam ring i4 is moved from the position of Figs. 3 and 6 to the position shown in Figs. 5 and 7, the bell-crank lever 23 will be rocked in a clockwise direction about its pivot 29 and thus swing the cleats 32 from the operative position of Fig. 6 to the inoperative position of '7 where they are clear of the tire.

Referring now more particularly to Figs. 3, 4 and 5, a pull rod :39 is connected to an expansion ring it by means of a bracket M. In Fig. 3, the expansion ring is has been rotated to such position that its cam surface Ma is in registry with the cam surface 30. of the fixed cam ring 53. In this position, the bell crank levers 28 are allowed to rotate to their extreme position in one direc tion and the cleats 32 are held snugly against the tread of the tire, by the tension of the spring arm 31.

When the pull rod 39 is moved to its forward position (Fig. 5), it moves the expansion ring M rotatively approximately 2 inches, on the base ring I 9, thus placing the cam surfaces i611 and Ma out of relation with each other and causing a separation of the cam ring is from the ring l3. This forward motion of the expansion ring M actuates the levers 28 and rotates the cleat assemblies rearwards about their pivots 29, thus swinging the cleats 32 free of the tire tread. When the cleats 32 are in engagement with the tread of a tire, the cleat ring 26 with its associated cleat assemblies is rotated with the wheel about the base i 9.

When the cleats are disengaged from the tread of the tire, a latch assembly is provided to stop the rotating cleat ring 29 at the position where none of the cleats are in engagement with the ground (Fig. 2). To do this, there is provided a latch assembly ti l (Figs. 9-13), comprising a base 45 having a lug :36 on one end, and guide ears 4! and 48 which slidably support a bolt 49 which is held in its projected position by the pressure of a spring 5e, against a shoulder 56a. Slots 5|, 52 and 53 are provided in the base It (Fig. 10) and a slot 22a is provided in the guide ring 22, for insertion of the latch assembly 44. Slots El, 52 and 53 are wide enough to permit a forward and backward movement of the latch assembly. A housing 53 is bolted to the underside of the base It! to slidably support the latch assembly 44 for backward and forward movements.

It will be noted from Figs. 3, a and 5 that a recess 55 is provided in the surface l3a of the cam ring [3 and recesses 58 and 51 are machined into the cam surface Ma of the expansion ring l4. When these two rings are positioned as shown in Fig. 3 and Fig. 10 (the cleats being on the tire tread), the recesses 55 and 56 are in alignment.

4 Attached to the base 45 of the latch assembly 44 are springs 58 which are fastened to the latch housing 54. Therefore, in this position, the springs 58 hold the latch assembly so that the lug 46 is seated in the recess 56 and the bolt 49 is not in contact with the cleat ring 26.

Upon slight rotation of expansion ring l4 by means of operating arm 46, to the position of Fig. 4, the lug 46 is carried up out of the recess 56 and onto a raised shoulder 59 of the cam member l4. This moves the latch assembly to the right, bringing the bolt 49 into engagement with the cleat ring 20 (see Fig. 11), the cleat ring being then still revolving with the wheel. In the meantime, the separation of the cam ring [4 from the ring l3 has caused the cleats 32 to be swung free of the tire tread, and the cleat ring 29 is spinning by reason of its inertia. A hole 69 is provided in the cleat ring 26, and when this hole has been carried to latching position, the bolt 49 which has been bearing against the face of the cleat ring (see Fig. 11) is forced into the hole 69 by pressure of the spring 56, thereby stopping the cleat ring in the desired position (see Figs. 2 and 12). Since by the time expansion ring It has moved out its full distance (Fig. 5), it has rocked the levers 28 to their extreme release position, against the tension of their spring arms 31, the friction of these levers is sufficient to continue to hold the cleat ring against idling movement from this stationary position. The complete movement of the ring M has been made to the position of Fig. 5, the recess 5! is in line with the recess 55, there allowing the lug 46 to fall back into the recess 5? and permit the latch assembly 44 to move to its original retracted position. This removes the bolt 49 from the slot 69 in the cleat ring, and there will be no rubbing of the bolt 49 on the ring 20 during travel of the vehicle.

At this time, the ring 29 is held against rotative movement only by the friction of the bellcranl: levers 28 on the cam ring it. Should the cleats 32 encounter some obstruction such as a curb or a rut in the roadway, the ring 29 with the cleat assemblies will rotate with the wheel until such time as the cleat assemblies reach approximately the position shown in Fig. 2, where none of the cleats have engagement with the road surface. the flexibility of the cleats 32 and their pivotallymounted arms 35 as above explained, provides against damage to the cleat elements when obstructions are encountered or the tire becomes flattened.

To again set the anti-skid device in operation, the driver will move the pull rod backwardly in the direction of the arrows in Fig. 3 to return the ring it from the position of Fig. 5 to that of Fig. 3, where the tails 28a of the bell-crank levers are released to allow the springs 36 to swing the cleats 32 across the tire.

The anti-skid elements can be moved to their operative and inoperative positions from the drivers seat, as by a lever 62 that is secured to a rock shaft 63 journaled in a bracket 64 on the floor board or dash board of the vehicle, the pull rods 16, extending to the respective rear wheels, being reciprocated through movement of the lever. A latch 65 is provided for releasably holding the lever in its on and off positions.

Referring now to Fig. 14, the pull rods 46 are connected to a cross bar 66 which, in turn is connected by a link 61 to a piston rod 98. Tubes 69 and I6 communicate with the front and rear ends of a cylinder. H that contains a liquid. Pis

This arrangement, together with axial movements on the base and having radial camming surfaces cooperatin with complementary camming surfaces on the stationary ring, guide rings fixedly mounted on the base, a cleat ring between the guide rings and rotatable on the base, cleat assemblies tiltably mounted on the cleat ring and having cleat fingers movable into positions across the tire tread, means yieldably urging the cleat assemblies and their fingers in one direction, with respect to their movements into and out of operative position on the tire tread, and connections between the cleat assemblies and the movable cam ring, for moving the cleat assemblies and their fingers in opposition to said yieldable means.

8. Antiskid device as recited in the next preceding claim, wherein the yielding means urges the cleat fingers against the tire tread and the movable cam ring moves the fingers to inoperative position.

9. Antiskid apparatus for wheels having yieldable treads, comprising a cleat ring mounted for rotative movement coaxial with the wheel, cleat member pivotally mounted on the ring, on axes generall tangential to the ring and each being of generally L-form with one leg extending radially of the ring and the other leg movable across the tire tread, the radial leg comprising two parts that are pivotally connected in endto-end relation, with the inner part pivotally connected to the ring and having an extension radially inward of its connection to the ring, a spring yieldably urging each cleat member toward the wheel and across the tire tread, a spring yieldably holding the said two parts in radial alinement, and manually-operable means engageable with said extensions, to rock the cleat member awa from the tire, in opposition to the first-named springs.

10. Antiskid apparatus for. vehicle wheels, comprising a cleat ring mounted for rotative movement coaxial with the wheel, cleat members pivotally mounted on the ring, on axes generally tangential to the ring and each being of generally L-form with one leg extending radially of the ring and being flexible under endwise thrusts and the other leg movable across the tire tread, the said one leg being detachabl connected to a radial portion of the other leg, for replacement when worn, and manually-operable means for rocking the cleat members on their pivotal mountings, in a direction to move their second-named legs away from the wheel treads.

11. Antiskid apparatus for vehicle wheels, comprising cleats each having a free end adapted to be moved across the tread of a tire, a radially-extending arm connected to the other end of each cleat, a supporting member upon which the inner ends of the arms are pivotally mounted, and which is supported for free rotative movement about the axis of the wheel when the cleats are free of engagement with the tire tread, means yieldabl urging the arms in a direction to move the cleats through arcuate paths into crosswise engagement with the tire tread, the cleat arms being held against radially outward movement when the cleats are on the tire tread but being flexible toward the axis of the wheel to allow radially-inward movement of the cleats upon deflation of the tire, and a manually-controlled device for rocking the cleats out of engagement with the tire tread in opposition to said yielding means, and for restraining rotative movement of the supporting member when the cleats are disengaged from the wheel tread, and no cleat is engaged between the tire and the road.

12. Antiskid apparatus for vehicle wheels, comprising cleats each having a free end adapted to be moved across the tread of a tire, a radially-extending arm connected to the other end of each cleat, a supporting member upon which the inner ends of the arms are pivotally mounted, and which is supported for free rotative movement about the axis of the wheel When the cleats are free of engagement with the tire tread, means yieldably urging the arms in a direction to move the cleats through arcuate paths into crosswise engagement with the tire tread, the cleat arms being held against radially outward movement when the cleats are on the tire tread but being flexible toward the axis of the wheel to allow radially-inward movement of the cleats upon deflation of the tire, and a manually-controlled device for rocking the cleats out of engagement with the tire tread in opposition to said yielding means, and for holding them against contact with the roadway.

13. Antiskid apparatus for vehicle wheels, comprising a cleat ring mounted for rotative movement coaxial with the wheel, cleat members pivotally mounted on the ring, on axes generally tangential to the ring and each being of generally L-form with one leg extending radially of the ring and being flexible under endwise thrusts and the other leg movable across the tire tread, and manually-operable means for rocking the cleat members on their pivotal mountings, in a direction tomove their secondnamed legs away from the wheel treads.

14. Antiskid apparatus for vehicles or" the type wherein the wheels are detachably secured to the outer faces of rotatable brake drums, comprising a base member adapted to be slid into position circumferentially of a brake drum when the wheel is detached from the drum, means for detachably connecting the inner end of the base member to a non-rotatable member of the vehicle, to hold the base member against rotating with the wheel and the drum, 2. cleatcarrying member rotatable on the base member, cleat members extending radiall from the cleatcarrying member, traction elements carried by the cleat members, and means for moving the traction elements into position to engage the roadway and to effect rotation of the cleat-carrying member with the wheel.

EDWARD J. HOFFMAN. WILLIAM G. HARDY. ADAM J. FRIES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,212,076 Rollings Aug. 20, 1940 2,427,510 Richardson Sept. 16, 1947 

